Cirsium mohavense

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Cirsium mohavense ranges from scattered sites in eastern California east in the Basin and Range Province of southern Nevada to southwestern Utah and nortwestern Arizona, mostly in Mojave Desert region. When Welsh proposed Cirsium virginense for a geographically limited group of plants from southwestern Utah and northwestern Arizona (and subsequently discovered in extreme southeastern Nevada), he indicated that its relationship to other western thistles was unknown. Subsequently, he indicated (S. L. Welsh 1983; Welsh et al. 1993) that the affinities of the taxon apparently lie with C. mohavense, but he did not attempt to distinguish C. virginense from C. mohavense (in the strict sense) because the latter was not known to occur in Utah. A. Cronquist (1994) attempted the distinction. The only character he used in his key was life span of the plants: biennial (C. mohavense) versus perennial, spreading by creeping roots (C. virginense). In the descriptions of the two taxa he elaborated on this character, indicating that C. mohavense is single-stemmed and C. virginense often multistemmed. In the remaining features the plants are very similar or overlap extensively.

Facts about "Cirsium mohavense"
apex architecture or shapespineless +
apex reliefscabrid +
apex shapeflattened +
array architecturecorymbiform + and paniculiform +
base architecture or shapebractlike +
base arrangementseparated +
base positiondistalmost +
base shapedecurrent +
blade shapeoblong-elliptic +, oblanceolate +, unlobed +, spinulose +, spiny-dentate + and pinnatifid +
branch orientationascending + and spreading +
chromosome count30 + and 32 +
collar colorationyellowish +
corolla colorationwhite +, pink + and lavender +
cypsela colorationstramineous + and brown +
face architecturewinged-petiolate + and sessile +
face countpresent +
face count or sizedecreasing +
face external texturegray-tomentose + and glabrate +
face otherprincipal +
face other or positionproximal +
face positionbasal +, cauline + and distal +
flowering timesummerfall +, jun +, jul +, aug +, sep + and oct +
habitatwet soil +, streams +, springs + and meadows in desert and desert woodland areas +
habitat moisturewet + and dry +
involucre external texturearachnoid + and glabrate +
involucre shapeovoid + and hemispheric +
lobe orientationspreading +
lobe shapelinear-lanceolate +, ovate-triangular +, entire + and dentate +
phyllary arrangementimbricate +
phyllary colorationinner +, brown + and stramineous +
phyllary orientationappressed +
phyllary positionouter + and middle +
phyllary shapelanceolate +, ovate + and linear-lanceolate +
spine fragilitystout +
spine orientationspreading +
spine sizeslender +
stem architecturesimple + and branched +
stem external texturegray-tomentose +
stem orientationerect +
whole organism architecturetaprooted +
whole organism life stylebiennial + and perennial +
wing architecture or shapespiny +